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Does sex really matter? Quantifying the importance of sexdisaggregated analysis for improving experimental reproducibility in an experimental fish model. BBSRC SWBio DTP PhD studentship 2023 Entry. PhD in Biosciences

   Department of Biosciences

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  Dr R Ellis, Dr E Santos  No more applications being accepted  Competition Funded PhD Project (Students Worldwide)

About the Project

The BBSRC-funded South West Biosciences Doctoral Training Partnership (SWBio DTP) involves a partnership of world-renown universities, research institutes and industry across the South West and Wales.

This partnership represents a distinctive group of bioscientists, with established international, national and regional networks, and widely recognised research excellence.

We aim to provide students with outstanding interdisciplinary research training within the following themes, underpinned by transformative technologies:

These are growth areas of the biosciences and for which there will be considerable future demand.

The award:

This project is one of a number that are in competition for funding from the South West Biosciences Doctoral Training Partnership (SWBio DTP). 

Programme Overview

You will be recruited to a broad, interdisciplinary project, supported by a multidisciplinary supervisory team, with many cross-institutional projects available. There are also opportunities to:

• apply your research in an industrial setting (DTP CASE studentships).

• undertake research jointly with our core and associate partners (Standard DTP studentships with an   


• work with other national/international researchers.

• undertake fieldwork.

Our structured training programme will ensure you are well equipped as a bioscience researcher, supporting careers into academia, industry and beyond. 

Project Description

Sex as an experimental factor is largely overlooked within the biological sciences, particularly outside a human biomedical model (Ellis et al 2017).

Nonetheless, a growing body of research has demonstrated significant, and often unexpected, impacts across a broad suite of behavioural, physiological and molecular systems within experimental organisms. When unaccounted for, sex based differences lead to an increase in unexplained experimental variance, a lack of reproducibility and the increased likelihood of misinterpretation of experimental outcomes (Tannenbaum et al 2019). Sex analysis is thus key for improving the accuracy and robustness of scientific research. Zebrafish represent the main experimental model for fish research globally, and constitute the second most used vertebrate species in research.

Nonetheless, major challenges exist in the use of this species as a model due to the impact of environment on sex determination, as well as the difficulty in sexing fish prior to experimentation. This often results in a failure to disaggregate or report sex in zebrafish experiments, or where tested a posteriori, leads to an increase in experimental animals used.

Results from other non-human vertebrate models have highlighted large significant differences between males and females with respect to responses to drugs, mechanisms in pain reception and stress induced gene regulation (Labonte et al 2017; Sorge et al 2015; Tannenbaum and Day 2017), whilst wider research has shown sex based differences impact behavioural, physiological, immunological, molecular and neurotoxicological functions. With temperature (and other key environmental factors) significantly influencing zebrafish sex, subtle variations in conditions across facilities can lead to unintended sex ratio bias. When left uncorrected, this significantly increases experimental variability, ultimately increasing animal numbers and reducing experimental reproducibility.

A key example of this is the use of zebrafish in regulatory testing of contaminants, particularly the OECD234 sex determination assay. Inability to sex individuals prior to experimentation, and thus ensure a balanced sex ratio, often results in a requirement of 800 individuals being tested to ensure sufficient numbers of males and females are assessed in control conditions. Use of a genetically determined species, where sex can be ascertained prior to experimentation (via non-invasive PCR assays), as is the case with medaka, could significantly reduce experimental animals used.

This project aims to quantify the importance of disaggregating sex in experimental research, and proposes to do so using a species in which sex is genetically determined, and thus stable – the medaka (Oryzias latipes).

Part Time and Flexible Study Options

Part time study options maybe available please discuss with the supervisor. For further information please see -

Due to complexities and restrictions associated with visas for part-time studies, we are currently unable to accept part-time international students to the programme.

Entry Requirements

Applicants should have obtained, or be about to obtain, a First or Upper Second Class UK Honours degree, or the equivalent qualifications gained outside the UK, in an appropriate area of science or technology. Applicants with a Lower Second Class degree will be considered if they also have Masters degree or have significant relevant non-academic experience.

In addition, due to the strong mathematical component of the taught course in the first year and the quantitative emphasis in our projects, quantitative/mathematical experience is needed. This can be demonstrated through one or more of the following:

  • Undertaking units as part of your degree that have a significant quantitative/mathematical component*
  • Maths or Physics A-level (grade B and above)

*Significant mathematical component examples include; maths, statistics, bioinformatics.

Applicants must ensure they highlight their quantitative/mathematical background within their application and to upload any supporting evidence.

To support accessibility to PhD training opportunities, these studentships are only available to applicants that have not previously obtained or about to obtain a PhD degree (or equivalent).

How to apply

The closing date for applications is midnight on Monday, 5 December 2022. Interviews will be held between 1st and 15th February 2023.

If you have any general enquiries about the application process please email [Email Address Removed].

Project-specific queries should be directed to the primary supervisor.

For further information and to submit an application please visit -

Selection Process:

Please note, the studentship selection process will take place in two stages:

For further information please go to -

Funding Notes

A fully-funded four year SWBio DTP studentship will cover
• a stipend* (at the standard Research Council UK rate; currently £17.668 per annum for 2022-23)
• research and training costs
• tuition fees (at the standard Research Councils UK rate)
• additional funds to support fieldwork, conferences and a 3-month internship
*An enhanced stipend is available for students with a recognised veterinary degree qualification (£24,789 per annum for 2022-2023). There may also be enhanced stipends associated with projects that have a CASE partner (CASE projects are highlighted as *CASE in the project lists).
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